Photo by michela lommi on Unsplash.

As a sustainability professional, I read a lot of articles on research related to pollution, in terms of both prevention and clean-up. This is the first in a category of posts on interesting sustainability news items that come across my desk. I wanted to share two articles I read today that both relate to slime of some sort. In a good way. They’re both related to plastics as well.

The first is doubly delightful to me because it not only relates to a possible inspiration for more recyclable bioplastics but also taught me about organisms I had never heard of before. As a “card-carrying biologist,” I take pride in knowing random information about lots of interesting life forms and am constantly amazed by the diversity of life on Earth. But there’s always more to learn! I’m a resident of the northern hemisphere, and the organisms in question are found in the tropics and humid forests in the southern hemisphere, so that’s why I wasn’t aware of their existence. Researchers at McGill University in Montréal, Quebec, Canada studying velvet worms found proteins in the slime these critters eject (really, they squirt it pretty forcefully) which allow that slime to transform from liquid to fiber (or as our Canadian neighbors say, “fibre”) and back again. Velvet worms look vaguely like crosses between caterpillars and worms, and they use their slime as defense or to capture prey. The slime hardens rapidly into a fibrous material that is as strong as nylon.

Why does this matter? Because petroleum-based plastics are ubiquitous, contain a slew of potentially harmful chemicals, and result in micro- and nanoscopic bits of pollution that have been found in virtually every environment on the planet, as well as in human breast milk, blood, the brain and other organs. We inhale and injest these bits all the time. We’re just beginning to understand the potential negative impacts of this plastic pollution on both human and environmental health. I promise to post more to this site on plastic pollution and potential impacts, but for now, if you want to learn more about the environmental and health impacts of plastics, I’ll point you to a recent report that my ISTC colleagues and I worked on, and suggest you skim through the chapter on plastics. I spent a lot of time gathering information for that chapter, and while I went into it knowing a fair amount about the complexity and multitude of issues surrounding plastic production and management, what I read still depressed the heck out of me. Plus, plastic recycling rates are abysmally low; in 2018, the overall recycling rate for various types of plastic was 8.7%. Meanwhile, research indicates that if current trends in production and waste management continue, roughly 12,000 metric tons of plastic waste will be in landfills or the natural environment by 2050. Can you conceive of how much plastic pollution that is? Me neither, but…it’s a LOT. We definitely need to reduce the amount of plastic we produce (starting with eliminating unnecessary single-use plastics as much as possible), and continue research on better, less toxic plastics that are easier to recycle or compost because we’ve so thoroughly integrated plastics into virtually every aspect of our lives that it isn’t realistic to think that we’ll ever return to a world without plastics of some kind. And that’s where this research about the velvet worms comes in. From the McGill University press release, “Traditional plastics and synthetic fibres are typically made using petroleum-based precursors and require energy-intensive processes to manufacture and recycle, often involving heat or chemical treatments. The velvet worm, however, uses simple mechanical forces –pulling and stretching – to generate strong, durable fibres from biorenewable precursors, which can later be dissolved and reused without harmful byproducts.” In other words, maybe someday, using the velvet worms as inspiration, we’ll be able to manufacture bio-based plastics that can be recycled without a lot of energy or potentially harmful chemicals. That would be pretty cool.

Be sure to check out the McGill University press release for a photo of a velvet worm; I think they’re pretty cute. If you want to dive deeply, check out the associated research article, “Conserved leucine-rich repeat proteins in the adhesive projectile slime of velvet worms.” See also the Wikipedia article on Onychophora, the phylum commonly referred to as velvet worms, for some more interesting pictures and facts about these nifty little critters.

The second slimy press release is from the American Chemical Society (ACS): Research Update: Okra, fenugreek extracts remove most microplastics from water. If you’ve ever eaten or prepared gumbo, you’re likely familiar with the fact that okra produces a slimy substance that serves as a thickener in that particular form of stew (though not all gumbo contains okra). The stringy slime from sliced okra and the gel from fenugreek seeds are non-toxic, plant-based polymers that could be used to attract, trap, and remove microplastics from water. From the ACS announcement: “Rajani Srinivasan and colleagues have been exploring nontoxic, plant-based approaches to attract and remove contaminants from water. In one set of lab experiments, they found that polymers from okra, fenugreek and tamarind stick to microplastics, clumping together and sinking for easy separation from water. Srinivasan spoke about successful demonstrations of the plant extracts in freshwater and ocean water at ACS Spring 2022, a meeting of the American Chemical Society. In this next stage of the research, they have optimized the process for okra and fenugreek extracts in various types of water.” The researchers found that okra and/or fenugreek extracts attracted and removed up to 90% of microplastics in ocean water, freshwater, and groundwater. They didn’t just test the efficacy of these substances on simulated pollution (i.e. water that they had mixed with microplastics to simulate pollution in real bodies of water). They started with those sorts of simulations but then collected real water samples from various Texas locations and tried out the substances on those. Again from ACS: “Polyacrylamide is currently used to remove contaminants during wastewater treatment, but the researchers say that okra and fenugreek extracts could serve as biodegradable and nontoxic alternatives.” Check out the Wikipedia article on polyacrylamide (particularly the section on “Environmental effects”). If you want to learn more about this research, see “Fenugreek and Okra Polymers as Treatment Agents for the Removal of Microplastics from Water Sources” published in the journal ACS Omega.

Some final fun facts–fenugreek seeds smell like maple syrup, and the herb is used as a folk remedy to improve milk production in lactating mothers. I have personal experience with this. I didn’t have my first baby until I was 30–after I had been diagnosed with breast cancer at the age of 28, gone through chemotherapy, radiation, and had a mastectomy, and been deemed cancer free. I wanted to breastfeed, but was concerned about producing enough milk given the situation. So, I took fenugreek supplements when nursing, on the off chance that it might help. I can’t confirm the efficacy of the supplements. With both of my kiddos, I combined breastfeeding with bottle feeding for a variety of reasons. I was too busy trying to work full time and take care of babies to carefully evaluate the folk remedy’s claims, and it’s not as if I had breastfed before, without the supplement. From what I’ve read, there’s no good evidence it helps with milk production, and you should be careful with it; people with peanut allergies can also have allergic reactions to fenugreek. But whether the supplements helped with milk production or not, I did notice that while I took them, if I got hot, my sweat smelled like maple syrup. It was a nice bonus.